JP5316773B2 - Paper stacking apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet stacking device on which a large amount of sheets discharged from a host device can be stacked and mounted with a shift tray that can be moved up and down, and an image forming apparatus including a sheet stacking unit.

  2. Description of the Related Art Conventionally, in a paper stacking apparatus equipped with a shift tray that can be moved up and down, as described in Patent Documents 1 and 2, the shift tray is moved up and down in accordance with the amount of paper to be discharged. There is a configuration in which sheets are stacked properly and properly.

  Japanese Patent Application Laid-Open No. 2004-133620 describes a mechanism for properly aligning the sheets stacked on the shift tray in the sheet stacking apparatus, in which the shift tray is lowered according to the stacking height of the sheets.

  Further, Patent Document 2 has a configuration in which the end fence that contacts the rear end of the sheet is made movable in accordance with the raising and lowering of the shift tray, thereby preventing the occurrence of problems such as disturbance in the stacking state and dirt. Have been described.

  In the configuration described in Patent Document 1, a member for detecting the stacking height of the paper is provided. However, the member for detecting the height is a rod-like member, and is only installed at one center. Therefore, there is a problem that the detection is unstable and the variation in detection due to the curl state of the paper is large.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, have a stability, and a paper stacking device capable of detecting a paper stacking height corresponding to various curling states in the paper width direction, and a paper An object of the present invention is to provide an image forming apparatus having a stacking unit.

In order to achieve the above object, the invention according to claim 1 is capable of stacking a plurality of sheets conveyed from the conveying unit, a conveying unit that receives and conveys the sheet discharged from the host device, and A shift tray that is horizontally held and can be lifted and lowered, and when the paper is stacked on the shift tray by a certain amount, the shift tray is lowered by a certain amount, and is loaded on the shift tray. A paper surface detecting means for detecting the paper stack height by contacting the rear end side in the paper width direction, and when the paper height detecting means detects that the stack height has been raised to a preset height. A tray driving means for lowering the shift tray, and a safety switch pressing unit for pressing a safety switch for stopping the operation of the shift tray when the shift tray is excessively raised With the door, so that the safety switch pressing member receives an operation of the sheet surface detection means is operated, characterized in that said safety switch pressing member and the sheet surface detecting means is provided independent axes, With this configuration, the shift tray status is properly determined by the paper surface detection member that detects the height of the paper loaded on the shift tray and the safety switch pressing member that detects that the shift tray has risen excessively. Since the braking is performed, the loading of the paper on the shift tray that can be moved up and down is performed in a balanced manner. In addition, since the paper surface detecting means and the safety switch pressing member are provided on independent shafts so that the safety switch pressing member operates in response to the operation of the paper surface detecting means, the operation of the safety switch is surely and easily performed. To be done

Invention according to claim 2, in sheet stacking apparatus according to claim 1 Symbol placing by means for detecting the presence or absence of a sheet on the shift tray, characterized in that the operational safety switch, this configuration, the paper The detection configuration can be simplified.

According to a third aspect of the present invention, in the paper stacking apparatus according to the first or second aspect , the shaft of the paper surface detecting means is provided closer to the shift tray installation position than the shaft of the safety switch pressing member. With this configuration, it is possible to shorten the arm member and the like constituting the paper surface detection unit with respect to the shift tray, so that the height detection error can be reduced.

According to a fourth aspect of the present invention, in the paper stacking apparatus according to any one of the first to third aspects, the paper surface detecting means is provided on an end fence that regulates a rear end of the paper stacked on the shift tray. With this configuration, the height of the paper that is pressed against the end fence and aligned can be recognized as it is, and the height is recognized at the rear end of the paper, that is, at a location closer to the paper discharge port. Therefore, the paper jam at the paper discharge port is unlikely to occur, and the shift tray can be accurately lowered according to the paper height.

According to a fifth aspect of the present invention, in the paper stacking apparatus according to any one of the first to fourth aspects, the paper surface detecting means includes a central portion on the rear end side in the width direction of the paper discharged to the shift tray, and both sides thereof. The sheet height can be detected in correspondence with various sheet curls in the width direction.

According to a sixth aspect of the present invention, in the paper stacking apparatus according to any one of the first to fifth aspects, the shift tray rises during the initial operation, and the paper loaded on the shift tray or the shift tray is a paper surface detecting unit. The tray driving means lowers the shift tray by a certain amount when it is pushed up by a certain amount, and the shift tray is lowered by a certain amount to stop and wait for the next operation. Can be started from a fixed position.

According to a seventh aspect of the present invention, in the paper stacking apparatus according to any one of the first to sixth aspects, a torsion spring that applies a load to the shaft of the safety switch pressing member is provided. Therefore, even if an excessive pushing force is applied, it is possible to prevent the safety switch from being pushed.

According to an eighth aspect of the present invention, in the image forming apparatus including an image forming unit that forms an image on a sheet and a sheet stacking unit that receives a sheet discharged after image formation, the sheet stacking unit is provided as the sheet stacking unit. The sheet post-processing apparatus according to any one of 7 to 7 is installed outside or inside the image forming apparatus main body.

  According to the present invention, the status determination of the shift tray is performed by the paper surface detection member that detects the sheet stacking height stacked on the shift tray that can be moved up and down, and the safety switch pressing member that detects that the shift tray is excessively raised. Is properly performed and braked, so that the loading of the paper on the shift tray capable of moving up and down is performed in a balanced manner.

1 is a schematic configuration diagram showing the overall configuration of a sheet stacking apparatus that is an embodiment of a sheet post-processing apparatus of the present invention. The perspective view which shows the shift conveyance mechanism part in this embodiment. The perspective view which shows the front end alignment mechanism part in this embodiment The front view which shows the jogger mechanism part in this embodiment The perspective view which shows the jogger mechanism part in this embodiment. The perspective view which shows the whole paper surface detection mechanism in this embodiment. The perspective view which shows the state when a paper inserts under a paper surface filler in the paper surface detection mechanism in this embodiment. The perspective view which shows the relationship between an end fence, a shift tray, a leg, and a paper surface filler in the paper surface detection mechanism in this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an overall configuration of a paper stacking apparatus as an embodiment of a paper post-processing apparatus according to the present invention. A sheet (paper) discharged from an image forming apparatus (not shown) is introduced from the direction of arrow A.

  As a configuration of the image forming apparatus, a publicly known one including an image forming unit that forms an image on a sheet and a sheet discharge unit that discharges the sheet after image formation can be used.

  In FIG. 1, 101 is a proof tray, 102 is a shift tray on which sheets are stacked, 103 is an elevator for raising and lowering the shift tray 102, 104 is a timing belt, 105 is a timing pulley, 106 is a worm gear, and 107 is a tray lifting motor. The timing belt 104, the timing pulley 105, the worm gear 106, and the tray lifting / lowering motor 107 constitute lifting / lowering means.

  Reference numeral 108 is disposed below the moving area of the shift tray 102 in the space 120 provided in the sheet stacking apparatus main body 100, receives the shift tray 102, and shifts the sheets stacked on the shift tray 102. It is a cart that is carried out together with the tray 102. In the lower part of the carriage 108, casters 190 that can move in all directions are provided at four locations in this example.

  In addition, 110 is a paddle that rotates counterclockwise in conjunction with a paper discharge roller 111 that discharges a sheet to the shift tray 102, 112 is a paper surface filler for detecting the paper stacked on the shift tray 102, and 113 is a paper discharge filler. A driven roller 114 urged by an elastic means (not shown) with respect to the paper roller 111 is an entrance roller as a conveying means for conveying the paper discharged from the image forming apparatus to the inside.

  The paper stacking apparatus can select an operation mode of a proof paper discharge mode, a straight paper discharge mode, and a shift paper discharge mode. In addition, the paper stacking apparatus is equipped with a CPU (Central Processing Unit) as a control unit, and communicates with an image forming apparatus (not shown) to control the operation of each unit in the paper stacking apparatus.

  The proof sheet discharge mode is an operation mode in which sheets are guided and stacked on the proof tray 101 through the sheet conveyance path L1. The straight paper discharge mode is an operation mode that leads to a post-processing device such as another paper stacking device provided at the rear stage of the paper stacking device through the paper transport path L2. The shift discharge mode is an operation mode in which sheets are discharged and stacked on the shift tray 102 through the sheet conveyance path L3.

  The shift tray 102 is placed on an elevator 103 that can be raised and lowered. The four corners of the elevator 103 are suspended by a total of four timing belts 104, and each timing belt 104 is wound around four corresponding timing pulleys 105. These timing pulleys 105 are linked by a worm gear 106 and a gear train composed of a plurality of gears, and are rotated synchronously by the driving force of the tray lifting / lowering motor 107 to lift and lower the elevator 103 together with the shift tray 102. Let

  Thus, since the power transmission system is via the worm gear 106, the shift tray 102 can be kept at a fixed position. When the elevator 103 is lowered to the lowest position, the shift tray 102 is placed on the carriage 108, whereby the paper loaded on the shift tray 102 together with the shift tray 102 is fed by the carriage 108 to the paper stacking apparatus main body 100. Can be carried out to the outside.

  The paddle 110 rotates counterclockwise in conjunction with the paper discharge roller 111 in the paper transport path L3, and strikes and presses the rear end portion of the paper discharged onto the shift tray 102 downward. Further, the paper stacked on the shift tray 102 pushes up the paper surface filler 112. Based on the movement of the sheet filler 112, the optical sheet sensor S3 detects the stacking height of sheets on the shift tray 102.

  When the paper surface sensor S3 is ON, the shift tray 102 is lowered by the tray lift motor 107, and the tray lift motor 107 is stopped after the paper surface sensor S3 is turned OFF. Therefore, every time the paper surface sensor S3 is turned on by the paper stacked on the shift tray 102, the shift tray 102 is lowered by a predetermined distance.

  S1 is a paper transport path sensor (hereinafter referred to as “entrance sensor”) provided at the paper carry-in entrance to detect the passage of the paper. S2 is a paper transport path sensor (hereinafter referred to as “paper ejection sensor”) for detecting the passage of paper in the paper transport path L3.

  Further, a driven roller 113 biased by elastic means such as a spring is pressed against the paper discharge roller 111, and a sheet is nipped between these rollers 111 and 113. The paper that is carried in is managed by the entrance sensor S1 and the paper ejection sensor S2, and the paper that is carried in from the image forming apparatus is ejected to the shift tray 102 by the entrance roller 114 and the paper ejection roller 111.

  The shift tray 102 is provided with a jogger 210 for aligning the width direction of the loaded paper, and on the paper discharge roller 111 side of the shift tray 102 is provided an end fence 64 for aligning the rear end of the discharged paper. A sheet stopper 71 is provided on the side of the shift tray 102 facing the end fence 64.

  Next, a configuration relating to paper detection in the shift tray of the present embodiment will be described.

  FIG. 2 is a perspective view showing a shift transport mechanism portion in the present embodiment.

  The shift conveyance mechanism unit 50 moves the paper discharge roller 111 and the driven roller 113 by a predetermined amount in the direction of the arrow in FIG. 2 (the arrow G1 is the front side of the paper stacking device main body 100 and the arrow G2 is the back side of the paper stacking device main body 100). By moving, the paper discharge position on the shift tray 102 is shifted to the near side or the far side.

  The paper discharge roller 111 and the driven roller 113 are connected to holders 51 and 52 that move in the direction of the arrow, and shafts 53 and 54 that connect them. The paper discharge roller 111 is rotated by the motor 55 regardless of the movement position in the directions of the arrows G1 and G2.

  That is, the driven gear 56 attached to the paper discharge roller 111 has gears 57 and 58 and a belt with respect to the drive gear 60 rotated by the stepping motor 55 regardless of the movement position of the paper discharge roller 111 in the arrow direction. 59 is connected.

  The holder 51 is provided with a rack gear 61, and the rack gear 61 is connected to a shift motor 63 via a pinion 62. The paper discharge roller 111 and the driven roller 113 are slid by a predetermined amount in the directions of arrows G1 and G2, with the position shown in FIG. 2 as the center position.

  The home positions of the paper discharge roller 111 and the driven roller 113 are set at the center position and are detected by the optical home position sensor S4. By rotating the pulse motor 63 by a predetermined amount with reference to the home position, the paper discharge roller 111 and the driven roller 113 are moved to the shift position.

  In the vicinity of the downstream side in the paper discharge direction of the paper discharge roller 111 and the driven roller 113, an end fence 64 for aligning the rear end portion (upstream side in the discharge direction) of the discharged paper is provided.

  FIG. 3 is a perspective view showing a tip aligning mechanism portion in the present embodiment.

  The leading edge aligning mechanism 70 is a mechanism for aligning the leading end portion (downstream in the discharging direction) of the paper discharged on the shift tray 102, and includes a stopper 71 whose position can be adjusted in the arrow H direction. The stopper 71 is attached to a slider 72, and the slider 72 is slidably guided by a shaft 73 extending in the arrow H direction as shown in FIG.

  The slider 72 is connected to a belt 76 that is stretched between pulleys 74 and 75. When the belt 76 is moved by the motor 77, the slider 72 moves in the arrow H direction together with the stopper 71, and the position is adjusted. The slider 72 is provided with a shielding plate 78, and when the stopper 71 moves to the home position, the shielding plate 78 is detected by the optical home position sensor S5.

  FIG. 4 is a front view showing a jogger mechanism portion in the present embodiment, and FIG. 5 is a perspective view showing the jogger mechanism portion.

  The jogger mechanism unit 200 controls the stepping motors 201 and 202 that control the movement of the pair of opposed joggers 210 (210F and 210R) in the paper width direction (the direction that is horizontal and orthogonal to the paper discharge direction), and the vertical movement. Stepping motor 203, gear 204 meshing with the gear of stepping motor 203, rotating shaft 205 to which gear 204 is attached, driving shaft 206 parallel to the rotating shaft, and joggers 210F and 210R connected to driving shaft 206 The sliders 207F and 207R, the sensors S6F and S6R that detect the sliders 207F and 207R, the filler 208 provided in the gear 204 that indicates the rotation state of the rotary shaft 205, and the sensor S7 that detects the filler 208 are included. Yes.

  The joggers 210F and 210R operate so as to widen and narrow the space between them. The state in which the filler 208 is detected by the sensor S7 is the home position. At this time, the joggers 210F and 210R are lowered.

  The joggers 210F and 210R are formed of a plate-like body, and the alignment portions 211F and 211R are located at the lowermost part of the joggers 210F and 210R. The facing surfaces of the alignment portions 211F and 211R are flat surfaces orthogonal to the shift direction G.

  Since the aligning portions 211F and 211R are configured as flat surfaces whose opposing surfaces are orthogonal to the shift direction G in this way, the joggers 210F and 210R are moved in the shift direction G so that they are stacked on the tray 102. The sheet bundles can be aligned by reliably bringing the aligning portions 211F and 211R into contact with and separating from the end surface of the sheet.

  The joggers 210F and 210R are provided such that the roots are sandwiched and pressed by the sliders 207F and 207R, and the joggers 210F and 210R do not hang down beyond a predetermined state depending on the positions of the sliders 207F and 207R, and are movable upward. It is a free configuration.

  The joggers 210 </ b> F and 210 </ b> R stand by at a receiving position with a predetermined facing interval that can receive the paper discharged from the paper discharge roller 111. Each time the paper is discharged from the paper discharge roller 111 and stacked on the shift tray 102, the joggers 210F and 210R move to the end surface position of the paper by performing an operation of narrowing the opposing space from the receiving position, The movement to widen the interval returns to the receiving position. By performing this series of alignment operations, the end faces of the sheets are aligned.

  Further, the paper discharge roller 111 repeats the shift operation in the direction of the arrow G1 for each discharged paper, and after completing the discharge of a predetermined number of sheets constituting the sheet bundle, the shift operation in the direction of the arrow G2 (shift in the direction of the arrow G1). The same distance as the operation) is repeated, and the next sheet bundle is sequentially stacked. When the shift direction is switched, the joggers 210F and 210R move to the retracted rotation position to enter the aligning member retracted state. In this retracted state, the joggers 210F and 210R perform a shift operation.

  For example, when the paper discharge roller 111 shifts to one jogger 210F, the other jogger 210R is disposed at a position where it abuts on the back side of the paper stacked on the shift tray 102 and the front “part” paper bundle. Will be. One main jogger 210F is positioned on the front side surface of the sheets stacked on the shift tray 102, and is positioned at the home position as the vertical position. Each time the shift operation of the discharge roller 111 is reversed, the rotary shaft 205 is rotated in a direction in which the arms 209F and 209R attached to the rotary shaft 205 press the bases of the joggers 210F and 210R downward. Move to.

  Each time a shift operation occurs, the opposite jogger is brought into contact with (placed on) the preceding “part” sheet bundle to align the discharged sheet bundle.

  6 to 8 are perspective views showing each configuration of the paper surface detection mechanism in the present embodiment.

  FIG. 6 is an overall view of the paper surface detection mechanism. The paper surface detection mechanism 80 is installed inside the end fence 64, a paper surface filler 112 that is a paper surface detection means is provided on the shaft 88, and a safety switch pressing lever 86 that is a safety switch pressing member is provided on the shaft 89. Yes.

  When the paper surface filler 112 rises and the shaft 88 rotates, the sensor filler 83 blocks the paper surface sensor S3, and the shift tray 102 is lowered by a certain amount. In addition, when the paper filler 112 is excessively raised, the lever 82 provided on the shaft 88 presses the safety switch pressing lever 86 and the safety switch 85 is turned on, so that the operation of the shift tray 102 is stopped.

  Further, the shaft 89 is provided with legs 87, and when the sheets are not stacked on the shift tray 102 or when the amount of sheets loaded is small, the shift tray 102 directly pushes up the legs 87 to thereby rotate the shaft 88. Rotates. Accordingly, the safety switch 85 is turned ON by the safety switch pressing lever 86, and the operation of the shift tray 102 is stopped.

  Further, the shaft 89 is provided with a torsion spring 90 that urges the shaft 89 counterclockwise. When the sheets are aligned, the sheet filler 112 is excessively pushed up by the sheet, and the safety switch 85 is turned on. To prevent it from happening.

  In this example, the paper filler 112 is provided at three positions on the rear end side in the width direction of the paper discharged to the shift tray 102, including the central portion and both sides thereof. A portion (edge) that is more angular than the portion is not in contact with the paper.

  FIG. 7 is a diagram illustrating a state when the paper P is inserted under the paper surface filler 112. The paper P discharged to the shift tray 102 is pushed in the D direction, is abutted against the end fence 64 and aligned, and enters under the three paper surface fillers 112. As a result, the paper filler 112 rises with the amount of paper loaded, and when the paper surface sensor S3 is raised until it is shut off, the shift tray 102 is lowered based on this detection.

  FIG. 8 is a diagram showing the relationship among the fence 64, the tray 102, the legs 87, and the paper surface filler 112. When there is a small amount of paper loaded on the shift tray 102, the paper surface filler 112 rises when the shift tray 102 rises excessively and contacts the end fence 64 before the safety switch 85 is turned on. The safety switch 85 is turned on when the shift tray 102 pushes the arm 87 before. During the initial operation, when the shift tray 102 is raised and the paper surface filler 112 is pushed up and the paper surface filler 112 blocks the paper surface sensor S3, the shift tray 102 is lowered by a certain amount and waits at a fixed position.

  In the above-described embodiment, a configuration example in which a paper stacking device independent from the image forming apparatus is installed outside the image forming apparatus and the paper discharged from the image forming apparatus is received has been described. It is also conceivable to install the paper stacking apparatus having the above-described configuration so as to be incorporated in the internal configuration of the image forming apparatus.

  The present invention is applied to an image forming apparatus of a copying machine, a printer, a facsimile machine, a sheet post-processing apparatus connected to a multifunction machine thereof, or a sheet post-processing apparatus incorporated in a paper stacking unit in the image forming apparatus. In particular, the present invention is effective when applied to a sheet stacking apparatus that stacks a large amount of sheets (sheets) on a vertically movable shift tray.

DESCRIPTION OF SYMBOLS 100 Paper loading apparatus main body 102 Shift tray 103 Elevator 111 Paper discharge roller 112 Paper surface filler 64 End fence 80 Paper surface detection mechanism 82 Lever 83 Sensor filler 86 Safety switch pressing lever 87 Leg 88, 89 Shaft 90 Torsion spring S3 Paper surface sensor

Japanese Patent No. 4091789 JP 2008-94612 A

Claims (8)

The shift tray includes a transport unit that receives and transports the paper ejected from the host device, and a shift tray that can stack a plurality of sheets transported from the transport unit and that is horizontally held and can be raised and lowered. A paper stacking device configured such that when a certain amount of paper is loaded on the shift tray, the shift tray is lowered by a certain amount, and is in contact with the rear end side in the width direction of the paper loaded on the shift tray. A paper surface detecting means for detecting the height, a tray driving means for lowering the shift tray when the paper height detecting means detects that the stacking height has been raised to a preset height, and the shift tray If excessively elevated, and a safety switch pressing member for pressing the safety switch for stopping the operation of the shift tray, the weaker receiving operation of the sheet surface detecting means As switch press member is operated, the sheet stacking apparatus characterized by said safety switch pressing member and the sheet surface detecting means is provided independent axes. 2. The paper stacking apparatus according to claim 1 , wherein the safety switch is operable by means for detecting the presence or absence of paper on the shift tray . 3. The paper stacking apparatus according to claim 1 , wherein the shaft of the paper surface detection unit is provided closer to the shift tray than the shaft of the safety switch pressing member . The paper stacking apparatus according to claim 1 , wherein the paper surface detection unit is provided on an end fence that regulates a rear end of the paper stacked on the shift tray . The sheet surface detection means, according to claim 1-4, wherein any one, characterized in that are provided at three positions of the center portion and its both sides in the width direction rear end of the sheet discharged to the shift tray Paper loading device. When the initial operation is performed, the shift tray is raised, and when the shift tray or the paper loaded on the shift tray pushes up the paper surface detection unit by a certain amount, the tray driving unit lowers the shift tray by a certain amount and stops. It is allowed sheet stacking apparatus according to claim 1 to 5 or 1, wherein said Rukoto. 7. The paper stacking apparatus according to claim 1 , further comprising a torsion spring that applies a load to the shaft of the safety switch pressing member . 8. The sheet according to claim 1, wherein the sheet stacking unit includes an image forming unit that forms an image on a sheet and a sheet stacking unit that receives a sheet discharged after image formation. the post-processing apparatus, an image forming apparatus is characterized in that provided outside of the image forming apparatus main body or incorporated therein.

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